Catalytic formation of carbon nanotubes on Fe-loading hexagonal mesoporous molecular sieve Fe/SiHMS and microporous molecular sieve Fe/NaY has been investigated. TEM pictures, together with the different porous properties of SiHMS and NaY, show us that the carbon nanotubes probably grow inside the channels of Fe/SiHMS and on the external surface of Fe/NaY. The Fe(2p) binding energy (BE) suggests a stronger interaction between SiHMS and the deposited iron oxide species than that between NaY and iron species. The BE of Si, O and Fe elements for Fe/SiHMS vary much before and after the catalytic synthesis of carbon nanotubes, whereas the BE for NaY changes little. The above XPS information can serve as a supplement to TEM analysis.